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Title: Tungsten dust impact on ITER-like plasma edge

The impact of tungsten dust originating from divertor plates on the performance of edge plasma in ITER-like discharge is evaluated using computer modeling with the coupled dust-plasma transport code DUSTT-UEDGE. Different dust injection parameters, including dust size and mass injection rates, are surveyed. It is found that tungsten dust injection with rates as low as a few mg/s can lead to dangerously high tungsten impurity concentrations in the plasma core. Dust injections with rates of a few tens of mg/s are shown to have a significant effect on edge plasma parameters and dynamics in ITER scale tokamaks. The large impact of certain phenomena, such as dust shielding by an ablation cloud and the thermal force on tungsten ions, on dust/impurity transport in edge plasma and consequently on core tungsten contamination level is demonstrated. It is also found that high-Z impurities provided by dust can induce macroscopic self-sustained plasma oscillations in plasma edge leading to large temporal variations of edge plasma parameters and heat load to divertor target plates.
Authors:
; ;  [1] ;  [2]
  1. University of California San Diego, La Jolla, California 92093 (United States)
  2. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
Publication Date:
OSTI Identifier:
22408002
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ABLATION; CONTAMINATION; DIVERTORS; DUSTS; HEATING LOAD; ITER TOKAMAK; PLASMA IMPURITIES; SHIELDING; TARGETS; TIME DEPENDENCE; TRANSPORT THEORY; TUNGSTEN IONS